Modify the LLVM assembly output so that it uses references to represent function...

Modify the LLVM assembly output so that it uses references to represent function attributes.

This makes the LLVM assembly look better. E.g.:

     define void @foo() #0 { ret void }
     attributes #0 = { nounwind noinline ssp }

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175605 91177308-0d34-0410-b5e6-96231b3b80d8